


The Superman Onesie

by SunflowerSprout



Category: Batman (Comics), Batman - All Media Types
Genre: Be the Batfam content you want to see in the world, Bruce Wayne is a Good Parent, Bruce is used as gymnastics equipment, Bruce loves his kid, Bruce tries not to laugh, Cameo by most of the Justice League, Dick Grayson is Robin, Dick has way too much pyjamas, Dick is a little troll, Fluff, Gen, Holy Pointy Ears Batman!, Justice League meetings gone wrong, Superman is confused, like very very fluffy, mentions of alfred, this is my first fic
Language: English
Status: Completed
Published: 2019-05-28
Updated: 2019-05-28
Packaged: 2020-03-20 20:15:46
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,516
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18999742
Author URL: https://archiveofourown.org/users/SunflowerSprout/pseuds/SunflowerSprout
Summary: There were certain unspoken agreements in the Justice League; facts that everybody agreed upon but never dared to say out loud.One of these unspoken agreements was that the weekly League meetings were most entertaining when held in the Batcave.





	The Superman Onesie

**Author's Note:**

  * For [lurkinglurkerwholurks](https://archiveofourown.org/users/lurkinglurkerwholurks/gifts).



> First of all, I'd like to present this as a gift to Lurkinglurkerwholurks, because Lurker is absolutely fantastic. I hope you liked this!
> 
> Second, this is the first fic I ever posted online. I'm a baby-ficcer and any commentary would be nice. I'm quite nervous actually.
> 
> Third, there's a lot of other fic-writers and people that I hope would like this as well. Without you guys, I doubt that I ever would have worked the courage to share this with the world.

There were certain unspoken agreements in the Justice League; facts that everybody agreed upon but never dared to say out loud.

For instance, it was a universal, but unspoken agreement, that Diana’s singing voice _wasn’t exactly_ as soft on the ear as the stereotypical princess tropes Disney would like the world to believe, but when a warrior princess starts singing, _out of fear for your very soul_ , you don’t tell her to shut up, even if her singing voice could cause the apocalypse alone.

Another universal, but unspoken agreement, was that Superman is a plant. 

_(I mean, Barry, consider it. He gets his energy from the sun – photosynthesis – and even though he has such a dense molecular structure, he’s still able to fly—)_

_(Yet he doesn’t produce any oxygen… But he is reactive to certain minerals! Hal, you’re right, Supes is a plant!)_

(The death-glare Superman gave them for the next few weeks terrified the both of them. They hadn’t verbally brought the subject up since.)

Another unspoken agreement was that the weekly League meetings were most entertaining when held in the Batcave.

Batman always tried to keep the League’s visits to the Cave to a bare minimum, convincing them to hold the meetings in the Watchtower, Hall of Justice or even the freezing Fortress of Solitude, rather than his Cave. But sometimes, options can get quite limited.

The first meeting held in the Batcave, to put it lightly, was Disastrous™. Not only did some of the Leaguers get lost in the labyrinth of cave tunnels after Batman gave them _very clear instructions_ (looking at you, Flash), but they all pleaded for a tour through his Trophy Room. Needless to say, it was quite hard to explain the Tyrannosaurus-Rex and the humongous penny. Only his years of intense training kept Batman from sighing and conveying his rather annoyed state of being in an easily readable expression. _Gotta keep up the stoic Bat-mysteriousness._

The total lost time already added up to two hours and seventeen minutes and _yes, he’s counting every moment down_ because Alfred’s making lasagne for dinner and he will not be missing Alfred’s Lasagne for explaining why he had a stash of Kryptonite in a little lead box and _no, Hal, for the fourth time, we’re not taking the Batmobile out for ‘a quick spin’. Stop asking._

After another half an hour dragged by, the League settled down enough for Superman to open the meeting.

“First of all,” the Man of Steel said, “the formation of the Justice League is still a fairly new idea to the world, and many people and authority figures might take negative to a handful of independent heroes to protect them and keep the Earth safe. I feel that we should start working on ways to convince them that threats like Reverse Flash and Sinestro,” he nodded towards Flash and Green Lantern, “cannot simply be dealt with by the military.”

Barry nodded and interjected, “Authority figures will also get frustrated with the collateral damage and the costs it will build up. Central City, for example, has begun a separate ‘Window Repair Funds’ to fix all the windows I accidentally break during my faster runs.”

Beside him, Hal snorted.

“It’s true!” Barry cried indignantly, “Go look it up online! The entire site explains how my speed and the vibrations I give off from running and the excess wind—“

“Flash,” Batman growled, effectively stopping Barry from launching into a full-speed, all-out rant.

“I donate monthly,” Barry pouted and dragged an oversized bowl of sweets closer, grabbing an amount that was totally overly self-indulgent. And probably a little rude, but hey, he was the Flash. If Diana decides to chastise him on childish behaviours, he will defend himself by bringing up his speedy metabolism. If he has to eat five times the amount of vegetables that a normal human being should, certainly he can help himself to five times the amount of sweets?

“Barry makes a valid point though,” Wonder Woman said, but instead of calling him out on his unhealthy life choices, she starts stuffing her own mouth with salt and vinegar chips. “Collateral damage. Definitely be a concern.”

“Very well,” Superman said and scribbled a little note. “Batman?”

Superman sat down and Batman stood silent as ever from his black office chair. _His Batcomputer chair that nobody but himself and Dick was allowed to sit on. Glare._ He took the notebook from Superman.

“NASA has been trying to reach out to the Justice League regarding our satellite, the Watchtower. They are interested in buying similar plans from us in order to upgrade the ISS and promote living in space.”

A quick muttering spread through the group, but as quick as it came, it was over. Batman’s scowl wasn’t something they had learned to oppose or ignore yet.

“Perhaps a list of pros and cons would be in order.”

Before any of the Leaguers could continue or say something else, a loud ‘clang’ reverberated through the cave. Batman’s scowl deepened by the slightest bit. Wonder Woman had jumped from her seat, ready to inspect and decimate any potential threats, but Superman and Batman both shook their heads at her. Diana sat back down, watching them with a wary glance.

An odd laugh echoed through the cave and mixed eerily with the faint squeals of the bats on the ceiling and bounced from the clammy walls. From the direction of the stairs, a small child-like figure came charging towards them.

“Uh, _Batman_ ,” Green Lantern whispered violently, trying to make sure that the Dark Night was aware of the little ball of energy speeding right towards him. Batman didn’t acknowledge him at all. Hal could swear that all reaction Batman had to the cackling voice, was his body tensing and standing firmer in the slightest movement, pulling his shoulders tight when the kid – it really was a kid! – jumped and used Batman’s shoulders as a springboard.

After a double flip through the air, the kid stuck a firm landing on the table, facing away from Batman.

_Was—was that a Flash-themed onesie?_

“Holy pointy ears, Batman, I didn’t know you _actually_ had friends!” The kid turned to stare Batman in the eyes. “Good thing Penny-One makes me keep a spare mask in the elevator!”

This time, no amount of training could keep Batman from sighing. “Is this about me grounding you from patrol for climbing down the Commissioner’s chimney to say hi to his daughter.”

“Holy peppermint and bacon, Batman, you _are_ good at this game,” the child declared and faced towards the League once more. He grabbed a bowl of toffees and strutted very much like a performer over to the Flash. “Can I sit with you, Uncle Barry?”

“Uhh… sure?” Barry replied a little dumbfounded and very confused. “Batman,” he whisper-shouted in distress.

“Robin.” The tone of voice Batman used was more exasperated than demanding, but the child’s innocent face just made him sigh again. Screw his anti-sighing Bat-training. “League, meet Robin. He is my ward and my… sidekick.”

“Sidekick is such a harsh word, B,” Robin said while getting comfortable in The Flash’s unsure grip. “I prefer the term… Hero Support. And don’t let him fool you with the whole ‘ward’ thing. I'm his lovechild with Lady Justice.”

If it wasn’t for the cowl, Batman would have pinched the little bit of soft flesh between his eyebrows in agony.

The amount of amusement and confusion in the room kept fluctuating, never really settling to one side. Batman pursed his lip but stood otherwise still. That was, until Flash spoke up, definitely more amused than confused, “So, _B_ bought you a Flash-onesie, huh?”

That seemed to revive enough courage in the powerhouses of the League to bombard Batman with dozens of questions about the little songbird that he hadn’t even bothered to mention to them before.

Needless to say, the meeting got rescheduled: Next time it will be held in the Watchtower, hundreds of miles away from little over-eager acrobat boys.

“Just save some space for dinner,” Batman commanded, eyeing the competition between Robin and Green Lantern. They were trying to see who could fit the most toffees in their mouth and so far Robin was destroying Hal, the rest of the League cheering for the small bird. “Penny-One is making lasagne.” 

**

The second time a meeting was supposed to be held in the Batcave, Bruce tried to postpone it with all his might. He almost fought Clark over it, but the alien reminded him that they had _really important_ matters to discuss. Also, Batman has an unfair advantage tucked away in a lead box, hidden in one of his utility belt’s pouches so _please, Diana, please tell Bats there won't be any Batman versus Superman charades allowed today._

But the Watchtower was under repairs, chunks of the Hall of Justice was missing after last week’s… _incident_ , and Superman’s Fortress of Solitude apparently wasn’t available. And Batman had just installed a Zeta tube in the cave.

Batman growled. If you’d ask him, this was all just a ploy to visit his cave again. Robin had recently been introduced to the world after some bystander caught a photo of his little bird giving Two-Face a proper kick under the chin. It was a pretty good photo too, Bruce would admit, Robin showing off his acrobatic skills and looking overall dramatic was fantastic and all, but he would have liked if Robin had stayed a rumour for a small while longer.

 _Well, they won't be seeing Dick tonight_ , Batman thought. He had the boy invite a friend over (of course Dick had _insisted_ upon Barbara. Bruce wouldn’t be surprised if Dick insists on _marrying_ her one day as well), and he has asked Alfred to keep a close eye on the two and to alert him at once if either of them disappeared from his eyes. This meeting will not go interrupted like the previous Batcave meeting.

Of course, that was the moment his phone decided to start vibrating so _conveniently_.

Two gleeful cackles filled the cave. Batman could have sworn that he saw Superman and Wonder Woman share a discreet high-five under the table, so he sent the most poisonous glare in their direction. Neither of them seemed to feel very threatened by it.

“Come on, BG!” the boyish voice called excited. An emerald ball of fluff dropped from the ceiling, followed shortly by a girl with a purple mask and thick locks of fire for hair.  
Hal was the first to burst out laughing while Diana tried to smother her giggles without much effort. The emerald ball of fluff was actually a Green Lantern onesie and ‘BG’ sported her own Wonder Woman pyjamas, completed with a crown on her head and a sword in her hand. Hopefully a fake sword by the way she swung it around.

Robin took a deep breath and Batman already rescheduled a double-meeting for the next week, both in the Fortress of Solitude. Whatever issue Superman has with it, Batman will give him three days to deal with it, but this meeting was necessary.

 _“From my shoulder to my fist,”_ the Boy Wonder shouted, _“Watch out, Evil, it’s my fist!”_ He playfully swung at the Wonder Woman girl, and she played along, easily dodging it.

The Leaguers laughed whole-heartedly at the kids’ fake battle. Even Batman had the slightest curl around the corners of his lips – but another unspoken agreement was to never comment on it unless you wanted to hang upside-down from one of Gotham’s streetlights. 

With their histrionic stage-combat, Barbara took another swing at Robin. Robin, never backing down from a challenge, faked being hit and vaulted himself into a backflip and gracefully sprawled himself out over the table. You could take the boy out of the circus…

“Sometimes you just gotta throw them with your tiara to remind them who they’re dealing with,” Barbara joked and winked at Diana, “Besides, there’s nothing like a good right hook to settle an argument!”

That elicited another chuckle from the Leaguers. The two tweens’ show continued and if there was any hope of continuing the meeting, it was harshly tossed out of some metaphorical window and left to be completely forgotten.

“She’s beauty, she’s grace,” Robin got to his feet and promptly added a spontaneous cartwheel, “She’ll punch you in the face!”

The red-head smiled innocently, “Where on earth did I park my invisible jet?”

“Okay, okay, wait I got it, BG,” Robin chuckled and struck the most serious pose his overly enthusiastic body could muster, “In brightest day, in blackest night, something-something, I hate yellow, Green Lantern!”

Not even Batman could keep it any longer, snorting at Hal’s flabbergasted expression. He was _extremely thankful_ that he had cameras _everywhere_ and that he recorded _anything and everything always and forever_ , because one day, he’d want to relive this exact moment. His ward butchering Green Lantern’s famous catchphrase was _simply golden_.

**

“No, Clark, we actually need to get work done. Interrupted meetings are far from productive. Besides, Dick has an upcoming string of tests that he needs to study for.”

“But Batma-a-a-a-an,” Clark whined.

“No meetings in the Batcave, period.”

Just as Batman uttered words that he considered final, several alarms in the Hall of Justice sounded, drenching the room in red light and loud, unforgiving noise. Batman wasn’t above smacking his palm against his forehead.

 _“Just. Last. Time,”_ he seethed and rushed off with an ecstatic Superman.

**

The longer the meeting continued, the more disappointed his fellow co-workers’ faces grew. Batman smirked and revelled in their discontentment. Negotiating with his eager ward to stall with his disruptive act until the end of their meeting in favour of some ice-cream on the next few patrols have totally been worth it.

Now Batman found utter satisfaction in Superman’s lost puppy eyes. He had been the one to suggest the Batcave so freely and charitably after the previous week’s compromise on both their bases as if the alien thought he owned the Batcave and not Batman.

Batman followed his last few words with a short period of silence, stalling on the dismissal of his teammates. He and Dick had discussed the meeting’s events, and this was his son’s cue. Sure enough, his presence was announced by his eerie cackle. They should trademark it. Probably.

Robin just _dropped down_ , and Batman realised that his son must have hidden on top of the lights for the entire evening. He made a little note to praise the boy on improving his stealth. Neither Superman nor one of the other Leaguers had realised that he had been hiding there if their surprise was anything to go by.

“Holy dinner time, Batman!” he shouted with an excessive amount of enthusiasm, “Penny-One just messaged me that it’s time to eat. Like, right now!” Robin looked nothing short of adorable in the Aquaman onesie and he started tugging at Batman’s cape. “Come on, B, nobody likes cold pasta!”

The child was set on dragging Batman out of the cave, but Batman seemed unfazed by his efforts. The other League members tried to hide their sniggers and chuckles behind their notes or a handful of toffees.

“How many onesies do the boy have?” Aquaman asked with clear amusement in his voice. They had all stood up and pushed their chairs in, now watching as the spectacle of a boy five times smaller than Batman himself, climb on Batman’s shoulders and flip off of his shoulders as if the big, brooding and slightly smiling man was some sort of gymnastics equipment.

“I trust you’ll all show yourselves out via the Zeta’s.” Superman nodded at Batman’s disguised order.

The rest of the League begrudgingly left, only Superman and Wonder Woman staying behind to clean up the last bits of the first successful Batcave-meeting. The little Robin kept pushing Batman up the stairs, hearing his faint grumble of, _“Holy cowls and capes, Batman, how heavy are you?”_

They watched as Batman played along to his ward’s silly antics, muttering, _“Oh, no, gravity’s increasing on me,”_ and Robin side-stepping the man so that Batman had to catch his balance before accidentally tumbling down the stairs, while chuckling, _“That’s not how it works, you big goof.”_

“Almost makes you wish you had one of your own,” Wonder Woman commented for Superman’s ears.

Superman watched the Dynamic Duo disappear into the elevator, heading the rest of the way upstairs in laughter and amused grunts. A fond smile stretched across the alien’s face. He was happy that his once-emotionless and permanently brooding teammate has found a shining beacon in his life to help guide him home.

“Yeah,” Superman sighed in an odd burst of sentimentality. “ _Almost_.”

**

Clark was a little surprised when Bruce invited him to come to the cave a little earlier than their scheduled weekly meeting’s appropriate time of arrival. Bruce didn’t sound hurt or in any danger when he called, but Clark was still a little bit… concerned.

It had only been recently that Bruce entrusted the rest of the main League members with his identity, thus adding Flash, Aquaman and Green Lantern in on the secret.

Just when he entered the cave, Bruce, not Batman, practically shoved him behind the Batcomputer, tossed him the Batsuit and ordered him swiftly and sharply, “Get dressed.”

Out of sheer experience, Superman didn’t even question the Detective and promptly stripped his Superman suit and tossed it out to Bruce. Once both of them were decent (it took a little help for Clark, all the armoury and padding of the Batsuit made it quite a complicated work of art), not-Superman glared viciously at not-Batman.

“The moment this meeting is over,” not-Superman started and not-Batman thought that it was extremely _wrong_ to have such a dark and brooding voice coming from his suit that basically screamed Sunshine and Hope, “you’re taking my suit off. I’ll incinerate it myself.”

Not-Batman smiled and almost laughed when not-Superman quickly cut him off, “And stay in character.”

Just for that, Clark thought, he will pull the funniest and weirdest faces possible throughout the entire meeting.

“If I may ask, wh—“

“Dick recently roped Alfred into buying him a Superman onesie. Tonight, I'm getting him back for all the interrupted meetings and heart attacks he gave me from jumping off the chandelier. He doesn’t suspect a thing.”

“Jumping off what now?” not-Batman replied calmly and mildly concerned. “Heart attacks?”

Not-Superman didn’t spare him another glance as the Zeta tubes began announcing the arrival of the other League members. If anybody noticed something throughout the meeting, they didn’t dare to say anything. Not-Batman wanted to laugh at it all. He wanted to laugh at Bruce for trying to sound all chirpy and obnoxiously hopeful and he wanted to laugh at himself every time he saw a glimpse of his own reflection in one of the glass cases, sporting the weighted cape and dark cowl that could strike fear in every villain’s heart. He wasn’t used to wearing anything this sombre and he tried, for the sake of his best friend who is also now not-Superman, to keep the emotionless face of the fearless Batman. It was extremely hard not to burst out into laughter from the silliness of the whole situation.

And then the much-awaited cackle echoed through the cave, bouncing from the walls, disturbing a few bats and sending shivers down not-Batman’s spine. If his super-hearing and supervision didn’t betray him, he saw the same shivers of anticipation and excitement in the other Leaguers, all except for not-Superman.

The sound of a grapple gun being fired and the string pulling taut was faintly audible, and in the next moment, the baby bird somersaulted onto the table. Only, he wasn’t wearing the Superman onesie that not-Superman expected him to.

“ _I am Vengeance, I am the Night!_ ” the kid growled, hiding comically behind the pyjama cape of the Caped Crusader pyjamas. “ _Robin, your shiny cape is distracting me from my nightly brooding session. Robin, don’t jump from the chandelier._ ”

The entire League was laughing now and not-Superman pulled his lips into a thin line. Dick had told him that he’ll be dressing as Superman tonight, and _technically_ , Clark was in the Batsuit.

“ _Yes Robin, you may drive the Batmobile. Drive it as fast as you like. Robin, patrol first, homework later._ ”

Well, Bruce thought and relaxed a bit, allowing himself the smallest smile. Anything if the kid is smiling.

“ _Robin, ‘aster’ and ‘chalant’ are not words and stop butchering the English language. Oh, no! Catwoman got away. Robin, sit down, she escaped and there’s nothing we can do._ ”

Still. Bruce refused to admit defeat.

“ _Robin, don’t be so surprised that I want to fight Superman. In the right mood, I’d fight my own reflection._ ”

It was an unspoken agreement, one that nobody ever dared to mention, that Justice League Meetings were the most entertaining when held in the Batcave where young little acrobat boys lived and reminded them that there’s still innocence and beauty in the world.

And it’s damn worth fighting for.

**Author's Note:**

> Kudos and comments would make my day!


End file.
